On a series of expeditions along the spine of the Andes Mountains, a team of high-climbing researchers has found mammalian life scampering through some of Earth’s harshest environments.
From 2020 to 2022, evolutionary biologist Jay Storz and colleagues trekked to the peaks of 21 volcanoes in South America. They’ve seen plumes of gas billowing from rocky vents, endured ferocious winds and subfreezing temperatures, and spent nights camping nearly 6,000 meters above the sea. “It’s really hard to exaggerate how inhospitable these super high elevation environments are,” says Storz, of the University of Nebraska–Lincoln.
The austere landscapes look like something you might see on Mars, he says — not the kind of places you’d expect to see wildlife. But for some mammals, such extreme locales are home. Multiple species of rodents live at or near the high-altitude peaks of Andean volcanoes, well above where alpine herbs, dwarf shrubs and other plants can grow, Storz and his colleagues report in a paper posted August 23 at bioRxiv.org.
Finding mammalian life above the vegetation line is “pretty unique and incredible, because what do they eat?” asks Jonathan Velotta, a biologist at the University of Denver who studies how animals adapt to extreme environments. He thinks Storz’s new work could change how scientists think about where life exists. It “suggests that animals live higher than we thought was possible,” Velotta says.
Storz and his colleagues are no strangers to altitudinous adventures. Three years ago, the researchers reported the world-record holder for highest-dwelling mammal. They found the animal, a yellow-rumped leaf-eared mouse, on the summit of Volcán Llullaillaco at an altitude of 6,739 meters, more than three quarters the height of Mount Everest (SN: 7/29/20).
But the scientists wondered if finding that mouse meant more mammals actually lived at extreme elevations — or if spotting it was just a fluke. The team…
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